Reptile Resource Center

Green Iguana

Iguana iguana

Green Iguanas are one of the top “disposable pets” in the world - which means they are often disposed of when the owners tire of caring for them or when the owner feels they have grown too large for their home.

CAGE TEMPS:

CAGE HUMIDITY:

65%-75%

WILD HISTORY:

Native to Central & South America and the Caribbean. Feral populations also exist in South Florida (including the Florida Keys), Hawaii, the U.S. Virgin Islands, the Grand Cayman Islands and the Rio Grande Valley of Texas. A small released or escaped colony also exists in Fort St. Louis. Green iguanas live in forest areas that are adjacent to water.

PHYSICAL CHARACTERISTICS:

Green Iguanas are long, slim bodied lizards (for their size) with tails that are usually longer than the lizard’s body itself. The long, strong tail can be whipped as a defense mechanism. If broken, the tail can regenerate itself, although never to the full beauty and strength of the original one. Iguanas are excellent swimmers; using the muscle and power of the tail, they propel themselves through the water with it, never using the legs to paddle or stroke. The toes of the iguanas are also long and have sharp claws for climbing trees. Iguanas are diurnal (active during the day) and arboreal (tree dwelling), however, they are also known to stay on the ground for extra warmth during cold weather. A healthy iguana generally ranges from a bright green to dark brown in color, depending on the species and sex of the animal. However, some sub-species can be blue, lavender, black or even pink, although these species are not available in the pet trade. The spikes that run along the back from the head to the tip of the tail help protect the iguana from predators. The dewlap (flap of skin hanging down from the chin and neck) helps regulate body temperature and aid in courtship displays. Green iguanas have a white photo-sensory organ on the top of their heads called the parietal eye. Unlike a normal eye, the parietal eye can only detect light & movement, but it can help the iguana “see” predators that may be approaching from above. Green iguanas have very sharp teeth lining the inner jawbone of both top and bottom jaws, similar to those of the extinct dinosaur, “Iguanadon”, which is where their name comes from.

NORMAL BEHAVIOR & INTERACTION:

Iguanas can be very difficult to train and therefore handle, which can sometimes make them challenging pets to own. Many people who buy iguanas when the iguana is a baby do not realize how big and powerful their small pet will become. Iguanas, especially males, can become aggressive and do have the ability to cause considerable damage with a bite. Do NOT purchase an iguana unless you are prepared to provide a large, roomy cage (8’ x 8’). A baby iguana may do fine in a large glass tank, but WILL outgrow it within a year’s time. Iguanas are not domesticated animals. In order to train your pet properly, you will need to devote much time to handling and training. Continuous handling and training on a daily basis can help ensure that your little baby does not easily revert back to its wild ways, but there is no guarantee. When picking up your pet, move slowly and carefully so that you do not scare him. Do NOT pick up your pet by the tail. Gently scoop him up under the belly, letting the feet dangle alongside your arm, and support the tail. Stroke your pet gently.

In nature, males become territorial and can engage in ritualized dominance struggles. Females may also have trouble getting along. For this reason, it is easiest for the pet owner to keep only one per enclosure.

Housing male iguanas together will create a dominant/submissive hierarchy and will result in one lizard becoming stressed to the point of illness, anorexia, and possibly death. Male iguanas also tend to be extremely aggressive toward one another and will fight, sometimes to the death. Female iguanas may be housed together IF there is ample space and food for each lizard. Considering the fact that one iguana needs and 8’ x 8’ space, two females will need more room than most keepers can provide.

Males and females should NOT be housed together, as the male iguanas may continually try to mate with the females; leaving the females exhausted, aggravated, and stressed. The female may stop eating and become extremely ill. Again, with enough room and supplies, this can be avoided, but the amount of room needed is most often prohibitive.

NOTE: Green iguanas should not be housed with lizards of another species.

Green iguanas can be very lethargic and lazy. They will choose the highest perch in their enclosure and often lie on it with all four legs hanging down..

FEEDING:

Green Iguanas are completely herbivorous.

Green iguanas require a precise ratio of minerals (2 to 1 calcium to phosphorus) in their diet. Iguanas should be fed a large fresh salad and fresh water every single day. The best fruits and vegetables for green iguanas are the following: Green beans, alfalfa (rabbit pellets), acorn squash, butternut squash, cactus leaves, collard greens, dandelion greens, endive (when mixed with other greens), mango, mustard greens, okra, papaya, parsnips, snap peas, turnip greens and watercress. If fed a steady diet of these selections, your iguana will be eating optimally. Be sure to feed a variety.

Other fruits and vegetables can be fed in moderation. Please see greenigsociety.org for an excellent feeding chart with precise nutrition details about common fruits and vegetables.

Juvenile iguanas often eat feces from adults in order to acquire the essential microflora to digest their low-quality and hard to process vegetarian diet.

SHEDDING:

Unlike snakes, lizards shed their skin in patches, not all in one piece. Your pet will become an overall dull color, and the skin over the eyelids may ‘pop’ at a certain point and make your lizard look like a bug-eyed bullfrog. Do not peel off the skin if it is not ready to come off. This can be dangerous and painful. Most lizard species will shed every 4-6 weeks. If the enclosure environment is ideal, the keeper often has no idea that their pet has shed, as it will happen more quickly and the lizard will often eat its own shed skin. In the wild, lizards have a much easier time with their sheds, as they are generally in a more naturally humid environment and have access to pools or bodies of water in which they can soak at will. Even lizards from arid areas find humid places to go during the shedding process, such as cold, moist burrows under the sand or caves. The shedding process happens when the lizard’s body begins to grow a new layer of skin; that new layer begins to separate from the old and a very thin layer of fluid forms between the two layers. If your pet’s enclosure is too dry, this fluid layer will not form properly, making it difficult for your lizard to shed properly. To create more humidity, the entire tank can be lightly spray misted twice a day during shedding time. Spray once in the morning and once later in the day. Make sure the later spray dries completely before lights go off for the night. Some lizards may also benefit from a ‘moist box’ during shedding time. This can be a Tupperware-like container (with the cover on) containing a bed of moist reptile terrarium moss. The container should be big enough for the entire lizard to be inside with an entry door cut in the side just large enough for the lizard to come and go at will. Keep the moss moist but not watery, and place the box on the heating pad in the tank.

If your lizard still has a hard time getting the shed completely off its toes, tail or head; help him by spraying the area with water and gently massaging the skin until it peels off. If the retained shed is severe and cannot be removed easily, see your exotic veterinarian.

SUPPLEMENTS:

Dust food with calcium supplement and vitamin supplements. As a rule, a growing juvenile's food (and a pregnant/gravid female’s) should be dusted more often than an adult's. Follow your veterinarian’s instructions for applying supplements to avoid over-supplementing food. Our veterinarian recommends dusting insects with a good quality calcium supplement fortified with vitamin D3, 2-3 times a week. (Avoid using a calcium supplement with added phosphorous, unless specifically directed by your veterinarian, since this can promote kidney disease.) Always consult your veterinarian for specific directions on supplementing your pet’s food, since there are many variables that go into determining the best supplementing regimen for a given animal.

WATER:

A large bowl of clean fresh chlorine-free water must always be available. Place it on the cool side of your lizard’s enclosure. Change it daily, or as needed, as your pet will most likely bathe in it as well. Lizards will often defecate in their water bowl, as the water seems to have a laxative effect on lizards!

All water given to lizards for drinking, as well as water used for misting, soaking or bathing must be 100% free of chlorine and heavy metals. (Not all home water filtration systems remove 100% of the chlorine and heavy metals from tap water). We recommend that you use unflavored bottled drinking water or bottled natural spring water; never use untreated tap water. If tap water is used, you should treat it with a de-chlorinating treatment. Do not use distilled water, which can cause severe medical problems, since it lacks minerals that are essential to important body functions. If only tap water can be used, at least de-chlorinate the water. De-chlorinator is available in the pet store fish department.

A daily misting or two with chlorine-free water will also be appreciated. However, care should be taken not to allow the enclosure to become damp. Also, do not mist less than two hours before turning the heat lamps off for the day.

SOAKING:

Lizards can benefit greatly from a good deep-water soak at least once a week. A Tupperware container makes a good lizard bathtub. Fill the container deep enough so the entire lizard’s body can be submerged under water, but the head can be out of water. The water should be nice and warm (about 68-70 degrees). Soak your pet for about a half hour at a time. This is especially helpful during a bad shed or when your lizard might be a bit constipated.

RECOMMENDED SUPPLIES:

Cage size should be about 8 feet wide and 8 feet high.

Large heat dome and heat bulb.

Under tank heater - placed under same side of tank as basking light. Do not use heat rocks.

Temperature/humidity gauge - do not stick to side of tank.

At least one dry hide house.

Shredded aspen substrate.

Large water bowl - big enough to soak or swim in.

Fluorescent UVB Bulb and housing.

Iguana book.

Live or plastic plants and branches.

HOUSING & ENVIRONMENT:

Lizards are ectothermic, or cold-blooded, which means they are dependent on the temperature of their immediate environment to regulate their body temperature. Therefore, we must create an environment with several heat gradients - warm on one end and cool on the other. With this set-up, your pet can go to either end depending on whether he needs to be warmer or cooler.

ENCLOSURE SIZE:Green iguanas are an arboreal forest species. They will usually choose the highest branch in the cage to perch on, so a very tall cage height is imperative. Cage size should be about 8 feet long x 4-6 feet deep x 8 feet high. Because of the large size requirements for iguana enclosures, cages often need to be hand constructed of wood and mesh which unfortunately allows humidity to escape easily. Try covering several sizes of the cage with Plexiglas or heavy sheet plastic to keep humidity levels high, as a low humidity level can create illness. Take care to not use toxic substances and supplies while building an iguana cage. Use waterproof wood surfaces with a low-toxin, water based polyurethane. Plywood and plexiglass are fine to use. If using silicone to seal joints, use only aquarium sealant. Be sure to allow more than enough time to allow all products to dry properly to avoid poisoning your new pet.

WARNING: Many iguana owners feel that their pet does not need a cage and will let the lizard wander freely in their house. This is NOT a good idea for many reasons. Iguanas left to their own devices will naturally try to climb to the highest point in the room, often knocking furniture and other household items over which can in turn fall on the iguana and injure him. Free roaming iguanas CANNOT receive the proper heat, humidity and UVB that they require to stay healthy. There is no way to provide these necessities and ensure that your pet will spend the required amount of time under those lights. Free house-roaming iguanas are also harder to keep tame.

IT IS NOT TRUE THAT A REPTILE WILL ONLY GROW AS LARGE AS ITS ENCLOSURE!!

COVER:Make sure the cage has an escape-proof metal mesh top. It should fit snugly onto the tank and have strong clips locking it on. It is important that the top is METAL mesh, as you will place the heat lamp directly on top of this cover.

HEAT PAD:Reptile heat pads can be adhered directly onto the underside of the glass bottom of the tank. Stick pad on the glass on one of the very far ends of the tank. For safety reasons, make sure to attach the rubber feet (contained in the box) at all four corners of the underside of the tank. This will allow air to circulate underneath the tank and prevent the heat from being trapped under the tank. If your enclosure has a wood bottom, or a larger area needs to be heated, a human-grade heat pad may be used on the low-medium setting, depending on the thickness of the wood. Do be sure to allow for proper ventilation for safety reasons. The human-grade pad can also be used for glass enclosures.

Heat pads specifically manufactured for reptiles are safe for pets to be in contact with and are safe to leave on 24 hours a day. DO NOT use reptile heat rocks. They heat unevenly and have caused severe thermal burns in lizards.

***Although your iguana may NOT spend much time on the floor of the enclosure, the heat pad will help contribute to the overall humidity and ambient temperature of the enclosure.

HEAT LAMP:Place the heat dome with the heat bulb on top of the cage directly on top of the metal mesh cover of the tank. Follow directions carefully with all products - READ THE INSTRUCTION SHEET!! Always choose fixtures with ceramic sockets and be careful to choose the socket that is properly rated for the wattage bulb that you will be using. Do not place the fixtures by dry wood or flammable fabrics. All heaters should be placed out of the reach of children and all pets - including cats and dogs. Be very careful to make sure that your caged pet cannot reach and touch the heating device in its own cage. A thermal burn to the face or body can be painful and life threatening.

UVB LIGHT:Exposure to UVB (ultraviolet B) light is critical in allowing an animal to synthesize vitamin D3 in their skin and metabolize calcium in their body. If an animal is not exposed to an adequate level of UVB light, it will gradually develop physical problems from the result of mineral deficiencies such as low blood calcium (hypocalcaemia), soft eggs (females), stunted growth and metabolic bone disorder, which can be fatal if left untreated. In addition, recent studies have linked sub-optimal vitamin D levels with poor immune system function.

All day-active (diurnal) indoor reptiles, amphibians, birds and hermit crabs should be allowed self-selected exposure to UVB lighting for up to 8-12 hours a day. This means they should be able to bask in the light but also get away if desired, much as they might in the wild. Many twilight-active (crepuscular) and night-active (nocturnal) species do get some exposure to the sun and may also benefit from low levels of UVB, which helps regulate their photoperiod and vitamin D levels as well.

Please see our additional “UVB Lighting for Companion Birds and Reptiles” for specific instructions for your particular pet and the UVB bulb that we recommend for him or her.

WATER BOWL:A very large water tub can be placed on the opposite end of the cage, along with another hide house, if desired. Many iguanas like to jump from their branches into their water dishes. If yours does, enlarge the water container so he does not hurt himself when jumping in. Iguanas LOVE water, so be sure to provide a large enough swimming and soaking tub.

SUBSTRATE:We recommend shredded aspen as a substrate. Shredded aspen will not cause impactions in the lizard if it is ingested by mistake and it is easy to clean - daily spot cleaning becomes easy by just removing the soiled portion of aspen. Newspaper, paper towels can also be used. If “reptile carpeting” is used, it MUST be kept extremely clean. The carpeting can foster the growth of bacteria and fungus, which can in turn be very dangerous to your pet. If you insist on using the carpet, purchase two so you can interchange them regularly.

BRANCHES & PLANTS:Iguanas love to climb, and additionally must have a basking area on the warm side of the tank. Choose branches that your iguana can climb on safely and lie on comfortably. The basking area can consist of branches and a platform positioned under the basking light so the iguana sits about six inches under the lamp. Sand blasted grape vine branches are available in the pet store; these serve as good sturdy climbing branches. Be careful of bringing in branches from outside, as they can house parasites.

TEMPERATURES:Cage temperatures should be monitored daily and kept at the temperatures listed at the top of this page. Use your reptile thermometer to check the temperatures in different places in the cage regularly to make sure they continually match the listed proper temperatures. * If the room temperature falls below 70 degrees at night, a supplemental infrared or ceramic heat fixture may be necessary. (These fixtures do not emit a light spectrum that is visible to the lizard, so it will not disturb him at night, but they WILL provide the necessary supplemental heat.) If your lizard does not receive the proper heat at the proper temperatures along with UVB light, he may become sick with issues such as respiratory disease and metabolic bone disease and will probably stop eating, as lizards have a hard time digesting their food without proper heat and light.

DAY/NIGHT LIGHT CYCLES AND HEATING:

All lizards must have distinct day and night periods in their enclosure to maintain their biological rhythms. Iguanas need 8-12 hours of daytime and 8-12 hours of nighttime. However, as the daylight hours change seasonally outside, daylight hours inside the tank should reflect the same.

HABITAT MAINTENANCE:

The entire tank should be cleaned thoroughly at least once every couple months with:

A mild dishwashing liquid (a weak dilution) in warm water, THEN

Vinegar & water (1:8) OR bleach and warm water (1:32)

Cage “furniture” should also be scrubbed clean with the same dilution.

RINSE OFF ALL SOAP AND BLEACH THOROUGHLY WITH PLAIN WATER BEFORE RE-INTRODUCING YOUR PET TO ITS ENCLOSURE!!

NEVER MIX VINEGAR AND BLEACH - IT CREATES A TOXIC SOLUTION

GROOMING & HYGIENE:

To reduce the risk of contracting and spreading salmonella poisoning, all handlers should wash their hands after handling any reptile.

SIGNS OF A HEALTHY ANIMAL:

Smooth, even skin; no traces of mites (small, reddish brown spots around nostrils, near ears and eyes); clear eyes, rounded, full body; strong, even, smooth jaw line; bright eyes; regular record of healthy feeding and defecating schedule. It is very important to keep a journal for each animal that records feeding, refusing, defecation, shedding, unusual behavior, changes in behavior and dates of bulb changes. This will help your veterinarian trouble-shoot any health issues. We recommend physical exams every year or two years with an exotic pet veterinarian for pet reptiles and amphibians. If your vet sees your pet regularly, many common conditions that afflict pet reptiles and amphibians can be caught and treated early. If not caught early enough or if left untreated, many of these conditions can become far worse if not fatal.